DRIVE UNIT

Abstract

The aim is to prevent a mobile object from moving unintentionally while stationary. The present drive unit comprises a frame, a drive wheel, an electric motor, a rotating element, and a braking mechanism. The drive wheel is rotatably supported by the frame. The electric motor is also supported by the frame. The electric motor is designed to drive the drive wheel. The rotating element is designed to rotate in conjunction with the drive wheel. The braking mechanism has an engagement range. The braking mechanism can be switched between a braking state and a non-braking state. In the braking state, the braking mechanism is adjusted such that the engagement range is in contact with the rotating element to brake its rotation.In the non-braking state, the braking mechanism is set such that the engagement area is out of engagement with the rotating element in order to allow rotation of the rotating element.

Description

CROSS-REFERENCE TO RELATED REGISTRATIONS

[0001] The present invention is based on application 2024-103574 dated June 27, 2024, the priority of which is hereby claimed and to which reference is hereby made. TECHNICAL AREA

[0002] The invention relates to a drive unit. BACKGROUND

[0003] It has been proposed to improve the performance of a low-speed moving object, such as a pallet truck, forklift, hand pallet truck, or wheelchair, by attaching a drive unit to the object (Japanese translation of the publication of International Application PCT / 2014-512307). This drive unit comprises a drive wheel, an electric motor, and so on. When the mobile object is moved by human power, the electric motor provides auxiliary power to support the human propulsion. BRIEF DESCRIPTION OF THE INVENTION

[0004] If a drive unit of the configuration described above is attached to the mobile object, there are concerns that the mobile object may move unintentionally while stationary. In light of this, the invention aims to provide a drive unit that prevents unintentional movement of the object while it is stationary.

[0005] A drive unit, according to a first aspect, comprises a frame, a drive wheel, an electric motor, a rotating element, and a braking mechanism. The drive wheel is rotatably supported by the frame. The electric motor is also supported by the frame. The electric motor is designed to drive the drive wheel. The rotating element is designed to rotate in conjunction with the drive wheel. The braking mechanism has an engagement range. The braking mechanism is switchable between a braking state and a non-braking state. In the braking state, the braking mechanism is set such that the engagement range is in contact with the rotating element to brake its rotation. In the non-braking state, the braking mechanism is set such that the engagement range is disengaged from the rotating element, thus allowing rotation of the rotating element.

[0006] In this configuration, the engagement area of ​​the braking mechanism engages with the rotating element, thereby braking its rotation. This prevents unintentional movement of an object while it is stopped.

[0007] A drive unit according to a second aspect refers to the drive unit according to the first aspect and is designed as follows. The engagement area is movable along an axial direction of the rotating element.

[0008] A drive unit according to a third aspect refers to the drive unit according to the first or second aspect and is designed as follows. The rotating element is a pinion. The engagement area is in contact with the pinion when the braking mechanism is in the braking state.

[0009] A drive unit according to a fourth aspect relates to the drive unit according to the third aspect and is designed as follows. The engagement area is arranged in a radial direction of the pinion, partially outside the tooth tips of the pinion.

[0010] A drive unit according to a fifth aspect refers to a drive unit according to the third or fourth aspect and is designed as follows. The engagement area is located in a radial direction of the pinion at a position outside a pitch circle of the pinion, in contact with the teeth of the pinion.

[0011] A drive unit according to a sixth aspect refers to the drive unit according to one of aspects one to five and further comprises a transmission element. The transmission element is designed to transmit a mechanical force between the electric motor and the drive wheel. The rotating element is attached to an output shaft of the electric motor. The electric motor and the engagement area are movable in one direction of extension of the transmission element.

[0012] A drive unit according to a seventh aspect refers to the drive unit according to one of aspects one to six and is designed as follows. The brake mechanism has a mounting plate and a brake body. The mounting plate is attached to the frame. The brake body is attached to the mounting plate. The brake body has an engagement area at its distal end.

[0013] A drive unit according to an eighth aspect refers to the drive unit according to the seventh aspect and is designed as follows: The electric motor is pivotally mounted on the frame about a pivot axis. The mounting plate is pivotally mounted on the frame about the pivot axis.

[0014] A drive unit according to a ninth aspect refers to the drive unit according to one of aspects one to eight and further comprises a drive wheel pinion. The drive wheel pinion is attached to a rotating shaft of the drive wheel. The rotating element is an electric motor pinion, which is attached to an output shaft of the electric motor.

[0015] A drive unit according to a tenth aspect relates to the drive unit according to the ninth aspect and is designed as follows. The engagement area is located at a position on or above an imaginary line connecting an axis of rotation of the electric motor pinion and an axis of rotation of the drive wheel pinion, in engagement with the teeth of the electric motor pinion.

[0016] Overall, the present invention makes it possible to prevent a mobile object from moving unintentionally while it is stopped. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a side view of a drive unit attached to a pallet truck; Fig. 2 is a side view of the drive unit; Fig. Figure 3 is a side view of the drive unit, from which one plate of a side plate pair, etc., has been removed; Fig. 4 is a sectional view of the drive unit along line IV-IV in Fig. 2; Fig. 5 is a Fig. 4. Corresponding diagram to illustrate a non-braking state of a braking mechanism; Fig. Figure 6 is a diagram illustrating the engagement state of an engagement area with an electric motor pinion. DETAILED DESCRIPTION

[0017] A preferred embodiment of a drive unit 100 attached to a pallet truck 200 is described in detail below with reference to the accompanying drawings. The drive unit 100 is attached to the mobile object. The movement of the mobile object is powered by human effort. The mobile object is moved at a low speed. The mobile object is used for transporting objects. The term "object" conceptually also includes a person, etc. Examples of the mobile object described above include a pallet truck, a hand pallet truck, a handcart, a wheelchair, etc., with the mobile object in the present embodiment being explained using the example of a pallet truck.In the following explanation, the term "forward" refers to a direction of movement of the pallet truck 200, which is pulled by the user, whereas the term "backward" and related terms refer to a direction of movement of the pallet truck 200, which is pushed by the user. <palettenhubwagen>

[0018] Fig. Figure 1 shows the pallet truck 200 with the attached drive unit 100 in a side view. It should be noted that the right side is in Fig. 1 of the front and the left side in Fig. 1 corresponds to the reverse side. How Fig. Figure 1 shows that the pallet truck 200 has a loading platform (a pair of fork arms 201, a control handle 202, and several vehicle wheels 204). It should be noted that each vehicle wheel 204 is a non-drive wheel. The drive unit 100 is attached to the pallet truck 200. <antriebseinheit>

[0019] Fig. Figure 2 shows the drive unit 100 in a side view. Fig. Figure 3 also shows the drive unit 100 in a side view, in which, however, one side plate of a pair of side plates 21, etc., has been removed. As in the Fig. 2 and Fig. As shown in Figure 3, the drive unit 100 has a frame 2, a drive wheel 3, a drive wheel pinion 4, an electric motor 5, an electric motor pinion 6 (example of a rotating element), a chain 7 (example of a transmission element) and a brake mechanism 8. The drive unit 100 also includes a battery 11, a mounting plate 12 and a pair of vehicle wheel covers 13. <rahmen>

[0020] Frame 2 serves to support the respective elements. Frame 2 comprises the pair of side plates 21. The side plates 21 are arranged widthwise at a distance from each other. The side plates 21 are fastened to each other with several bolts, etc. <Antriebsrad und Antriebsradritzel>

[0021] The drive wheel 3 is rotatably mounted in the frame 2. Specifically, a pivot shaft 31 of the drive wheel 3 is rotatably mounted in the frame 2 via a bearing element, etc. The pivot shaft 31 of the drive wheel 3 extends in the lateral direction. The pivot shaft 31 rotates as a unit with the drive wheel 3.

[0022] The lower end of the drive wheel 3 is positioned below that of the frame 2. In other words, the drive wheel 3 is in contact with a ground surface. The frame 2 is preferably not in contact with the ground surface. The drive wheel 3 rolls on the ground surface. It should be noted that in the present preferred embodiment, the drive unit 100 comprises only a single drive wheel 3, but alternatively, it can comprise several drive wheels.

[0023] The drive pinion 4 is attached to the rotating shaft 31 of the drive wheel 3. The drive pinion 4 is designed so that it rotates as a unit with the drive wheel 3. <Elektromotor, Elektromotor-Ritzel und Kette>

[0024] When the pallet truck 200 is moved by the user's human power, the electric motor 5 provides auxiliary power to assist the pallet truck's movement. It should be noted that the electric motor 5 can deliver torque to initiate movement of the pallet truck 200 while the user operates a control lever 200. The electric motor 5 is configured to drive and rotate the drive wheel 3.

[0025] The electric motor 5 has an output shaft 51. The output shaft 51 rotates as a unit with a rotor of the electric motor 5. The output shaft 51 extends in the lateral direction. It should be noted that the direction of extension of the output shaft 51 is also referred to as the axial direction; that is, the lateral direction is synonymous with the axial direction.

[0026] The electric motor pinion 6 is attached to the output shaft 51 of the electric motor 5. The electric motor pinion 6 is designed to rotate as a single unit with the output shaft 51. The electric motor pinion 51 is positioned in front of the drive gear pinion 4. Furthermore, the electric motor pinion 6 is positioned above the drive gear pinion 4.

[0027] The chain 7 is designed to transmit a mechanical force between the electric motor pinion 6 and the drive wheel pinion 4. In other words, the chain 7 is tensioned over the electric motor pinion 6 and the drive wheel pinion 4.

[0028] The electric motor pinion 6 is rotated by the chain as a unit with the drive wheel pinion 4; furthermore, the drive wheel pinion 4 is rotated as a unit with the drive wheel 3. In other words, the electric motor pinion 6 is designed to rotate in conjunction with the drive wheel 3.

[0029] The electric motor 5 is supported by the frame 2. The electric motor 5 is positioned in front of the drive wheel 3. The electric motor 5 is movable in the direction of travel of the chain 7. In other words, the electric motor 5 is movable in both directions, allowing the electric motor pinion 6 to move towards and away from the drive wheel pinion 4.

[0030] In detail, the electric motor 5 is attached to the frame 2 such that it can pivot about a pivot axis O. More precisely, the electric motor 5 is attached to a plurality of bolts 101, each extending in the width direction, to secure the pair of side plates 21. It should be noted that one of the bolts 101 serves as the pivot axis O. The remaining bolts 101 secure the pair of side plates 21 by means of a plurality of elongated hole pairs provided in each pair of side plates 21. This allows the electric motor 5 to pivot about the pivot axis O.

[0031] When the electric motor 5 rotates clockwise around the swivel axis O in Fig. When the 3 is turned, the electric motor pinion 6 moves away from the drive wheel pinion 4. This allows the chain 7 to be tightened if it is slack. In the Fig. 2 and Fig. Figure 3 shows a state that is produced after the electric motor 5 has been rotated clockwise. <bremsmechanismus>

[0032] The braking mechanism 8 is designed to brake the rotation of the drive wheel 3 in the drive unit 100. The braking mechanism 8 can be switched between a braking state and a non-braking state. In the braking state, the braking mechanism 8 brakes the rotation of the electric motor pinion 6. It should be noted that the electric motor pinion 6 rotates in conjunction with the drive wheel 3, so that when the rotation of the electric motor pinion 6 is braked, the rotation of the drive wheel 3 is also braked.

[0033] In the non-braking state, however, the braking mechanism 8 allows the rotation of the electric motor pinion 6. In other words, in the non-braking state, the braking of the rotation of the electric motor pinion 6 by the braking mechanism 8 is lifted.

[0034] The brake mechanism 8 comprises a mounting plate 81 and a brake body 82. The mounting plate 81 is attached to the frame 2. Specifically, the mounting plate 81 is attached to the pair of side plates 21 by means of the bolts 101 to which the electric motor 5 is attached. In this way, the mounting plate 81 is pivotally attached to the frame 2 about the pivot axis O. It should be noted that the mounting plate 81 is arranged such that it covers an opening 211 provided in one of the plates of the pair of side plates 21.

[0035] The brake body 82 is attached to the mounting plate 81, which allows the brake body 82, together with the mounting plate 81, to pivot about the pivot axis O. In other words, the brake body 82 is movable in the direction of extension of the chain 7 in a manner comparable to the electric motor 5. Specifically, the brake body 82 pivots as a unit with the electric motor 5. The brake body 82 extends such that it passes through the opening 211 provided in a plate of the side plate pair 21.

[0036] Fig. Figure 4 shows the drive unit 100 in a sectional view along line IV-IV in Fig. 2. A non-braking state of a braking mechanism is in Fig. 5 in one Fig. 4 corresponding diagrams. It should be noted that the braking mechanism in Fig. 4 is brought into braking position. How the Fig. 4 and Fig. As shown in Figure 5, the brake body 82 has an engagement bolt 821 (example of an engagement area) at its distal end. By actuating an actuating section 822 of the brake body 82, the engagement bolt is axially advanced or retracted. In other words, the engagement bolt 821 is movable along the axial direction of the electric motor pinion 6.

[0037] The engagement bolt 821 is axially advanced or retracted by the rotation of the actuating section 822. The brake body 82 is designed, for example, as a detent bolt. When the engagement bolt 821 is axially advanced, it engages with the teeth of the electric motor pinion 6. When retracted, however, the engagement bolt 821 disengages from the electric motor pinion 6. Fig. Figure 4 shows the extended state of the engagement bolt 821. When retracted, the engagement bolt 821 moves to the right. Fig. 4 is moved and thereby disengaged from the teeth of the electric motor pinion 6.

[0038] When the brake mechanism 8 is engaged, the engagement pin 821 is engaged with the teeth of the electric motor pinion 6. Specifically, when the brake mechanism 8 is engaged, the engagement pin 821 projects towards the electric motor pinion 6 and thus engages with its teeth. Conversely, when the brake mechanism 8 is disengaged, the engagement pin 821 is disengaged from the teeth of the electric motor pinion 6. Specifically, when the brake mechanism 8 is disengaged, the engagement pin 821 is retracted away from the electric motor pinion 6 and thus disengaged from its teeth.

[0039] Fig. Figure 6 shows in a diagram the engagement state of the engagement bolt 821 with the electric motor pinion 6. When the brake mechanism 8, as in Fig. As shown in Figure 6, when in the braking state, the engagement pin 821 is engaged with the teeth of the electric motor pinion 6. In other words, the engagement pin 821 is positioned between any pair of adjacent teeth.

[0040] The engagement pin 821 is arranged in a radial direction of the electric motor pinion 6, partially outside the tooth tips of the pinion. In other words, the engagement pin 821 partially projects outwards from a gap between the pair of adjacent teeth. Specifically, the engagement pin 821 projects outwards by half or more than half of the gap between the pair of adjacent teeth. The engagement pin 821 is located outside a pitch circle of the electric motor pinion 6 in the radial direction of the electric motor pinion 6 and is in contact with the teeth of the electric motor pinion 6.

[0041] As in Fig. As shown in Figure 3, the engagement of the engagement bolt 821 with the teeth of the electric motor pinion 6 takes place on an imaginary line L, where the imaginary line refers here to a line that connects the axis of rotation of the electric motor pinion 6 and that of the drive wheel pinion 4.

[0042] According to the drive unit 100, which is designed as described above, the drive wheel 3 can be secured against rotation when the pallet truck 200 comes to a stop by bringing the brake mechanism into the braking state, i.e., in other words, by actuating the actuating section 822 of the brake body 82, so that the engagement bolt 821 engages with the pinion 6 of the electric motor. This allows the pallet truck to be held in the stopped state. <Batterie und Montageplatte>

[0043] As in the Fig. 2 and Fig. As shown in Figure 3, the battery 11 is attached to the frame 2 via the mounting plate 12. The battery 11 supplies the electric motor 5, etc., with electrical energy. The mounting plate 12 projects forward and laterally from the battery 11 to prevent the battery 11 from colliding with an obstacle, etc. The outer circumference of the mounting plate 12 consists of an elastic body with metal core rods inside. <fahrzeugradabdeckungen>

[0044] Each cover of the pair of vehicle wheel covers 13 is designed to prevent the user, etc., from coming into contact with one of the vehicle wheels 204 of the pallet truck 200. Each vehicle wheel cover 13 is positioned in front of the corresponding wheel 204 of the vehicle and is attached to the frame 2.

[0045] In detail, each wheel cover 13 is attached to the frame 2 by a bolt 102. Furthermore, each wheel cover 13 has a cutout 131. Each wheel cover 13 is hooked onto a projecting section 103, which extends from the frame 2 through the cutout 131. This prevents rotation of the respective wheel cover 13. It should be noted that the projecting section 103 and the cutout 131 of each wheel cover 13 overlap with the vehicle wheels 204 in a side view. [Modifications]

[0046] A preferred embodiment of the invention has been described above. However, the invention is not limited to this embodiment, but allows for numerous modifications without deviating from the core of the invention. It should be noted that, in principle, all described modifications can be applied simultaneously. (a) The rotating element provided as an object to be braked by the braking mechanism 8 may not be the pinion 6 of the electric motor. The braking mechanism 8 may, for example, also brake the pinion 4 of the drive wheel. Apart from this configuration, the braking mechanism 9 may also brake another pinion located between the pinion 6 of the electric motor and the pinion 4 of the drive wheel. Alternatively, the object to be braked by the braking mechanism 8 may not be in the form of a pinion. (b) In the embodiment described above, the engagement bolt 821, which can be pushed forward and retracted, is provided as the engagement area of ​​the braking mechanism. However, the engagement area of ​​the braking mechanism is not limited to this. The engagement area of ​​the braking mechanism can, for example, be a plate shaped along the teeth of the electric motor pinion 6. In this case, the plate is designed such that it can be brought into or out of engagement with the teeth of the electric motor pinion 6 when it is moved forward and backward toward or away from the electric motor pinion 6. (c) A speed reducer can be installed between the electric motor 5 and the drive wheel 3. In this case, the speed reducer is arranged between the electric motor pinion 6 and the drive wheel pinion 4. The speed reducer reduces the rotational speed of the electrical energy generated by the electric motor 5 and transmits the reduced energy to the drive wheel 3. (d) The engagement bolt 821 can be engaged with the teeth of the electric motor pinion 6 at a position above the imaginary line L. REFERENCE MARK LIST 2 frames 3 drive wheel 31 Rotary shaft 4 pinion drive wheel 5 electric motor 51 Output shaft 6-pinion electric motor 7 chain 8 Brake mechanism 81 Mounting plate 82 brake bodies 821 engagement bolts 100 drive units QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 512307

[0003] < / fahrzeugradabdeckungen> < / bremsmechanismus> < / rahmen> < / antriebseinheit> < / palettenhubwagen>

Claims

[1] Drive unit comprising: a frame; a drive wheel (3) rotatably supported by the frame an electric motor supported by the frame, designed to drive the drive wheel; a rotating element designed for rotation in conjunction with the drive wheel; and a braking mechanism with an engagement range, wherein the braking mechanism is switchable between a braking state and a non-braking state, wherein the braking mechanism in the braking state is set such that the engagement area is in engagement with the rotating element to brake the rotation of the rotating element, and wherein the braking mechanism in the non-braking state is set such that the engagement area is out of engagement with the rotating element to allow rotation of the rotating element. [2] Drive unit according to claim 1, wherein the engagement area is movable along an axial direction of the rotating element. [3] Drive unit according to claim 1, wherein the rotating element is a pinion and the engagement area is engaged with the teeth of the pinion when the braking mechanism is in the braking state. [4] Drive unit according to claim 3, wherein the engagement area in a radial direction of the pinion is arranged partly outside the tooth tips of the pinion. [5] Drive unit according to claim 3, wherein the engagement area in a radial direction of the pinion is engaged with the teeth of the pinion at a position outside a pitch circle of the pinion. [6] Drive unit according to claim 1, further comprising: a transmission element designed to transmit a mechanical force between the electric motor and the drive wheel, wherein the rotating element is attached to an output shaft of the electric motor and wherein the electric motor and the engagement area are movable in one extension direction of the transmission element. [7] Drive unit according to claim 1, wherein the brake mechanism comprises a mounting plate and a brake body, the mounting plate being attached to the frame and the brake body being attached to the mounting plate, and wherein the brake body has the engagement area at its distal end. [8] Drive unit according to claim 7, wherein the electric motor is pivotably attached to the frame about a pivot axis and the mounting plate is attached to the frame so that it can pivot around the pivot axis. [9] Drive unit according to claim 1, further comprising: a drive wheel pinion that is attached to a rotating shaft of the drive wheel, wherein the rotating element is an electric motor pinion that is attached to an output shaft of the electric motor. [10] Drive unit according to claim 9, wherein the engagement area is located at a position on or above an imaginary line connecting an axis of rotation of the electric motor pinion and an axis of rotation of the drive wheel pinion, engaging with the teeth of the electric motor pinion.

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